Interchangeable glass and metal vacuum coffee maker



Get. 30, 1951 A. c. WILCOX 2,573,237

INTERCHANGEABLE GLASS AND METAL VACUUM COFFEE MAKER Filed Aug. 50, 1949 4 Sheets-Sheet 1 Fig.1

Z IN V EN TOR.

Alberfi C. Wilcox- 56 W ivgd g ATTORNEYS Oct. 30, 1951 INTERCHANGEABLE Filed Aug. 30, 1949 A. C. WILCOX GLASS AND METAL VACUUM COFFEE MAKER 4 Sheets-Sheet 2 x m X j INVENTOR. V ,g 14m; 0 Wilcox rdzy A TT OEIVEYS Oct. 30, 1951 c, WILCOX 2,573,237

INTERCHANGEABLE GLASS AND METAL. VACUUM COFFEE MAKER Filed Aug. 50, 1949 4 Sheets-Sheet 3 I N VEN TOR. fllb em" 6. W1 Z 60.1:

$ @QQQ! A TTORNE VS @CiJ. 30, 1951 Q wlLCOX 2,573,237 7 INTERCHANGEABLE GLASS AND METAL VACUUM COFFEE MAKER Filed Aug. 50, 1949 4 Sheets-Sheet 4 IN VEN TOR.

zberiaWizcm 6 A TTOR/VE Y6 Patented Oct. 30, 1951 UNITED STATES PATENT OFFICE INTERCHANGEABLE GLASS AND METAL VACUUM COFFEE MAKER The invention relates to vacuum coifee makers, and has for an-object to simplify such coffee makers whereby the manufacturing cost may be lower, so as to sell to the trade at a very low popular price for automatic electric coilee makers.

Another object is to provide such a vacuum coffee maker whereby the housewife has the 0ption of obtaining a full automatic electric vacuum coffee maker in either glass or metal.

A further object is to provide such a vacuum coffee maker in which the lower water container is quickly and easily detachable from the heating means, whereby it may be thoroughly washed.

A still further object is to provide such a vacuum coffee maker in which the heating means is located in a separable base having spring clips therein for snapping the lower water container into or out of the base.

Another object provides such a construction in which the base containing the heating means can remain attached to the lower container after brewing and when serving the coifee, so that the coffee beverage in .the lower container may be kept not until used.

A further object is to provide such a vacuum coffee maker" in which the base is provided with a metal shell to receive a reduced well at the bottom of the lower water container, said shell having a curved bi-metal strip connected to its outer side for operating a switch for controlling the heating circuit.

The above objects together with others which will be apparent from the drawings and following description, or which may be later referred to, may be attained by constructing the improved vacuum coffee maker in the manner hereinafter described in detail and illustrated in the accompanying drawings, in which- Figure 1 is a longitudinal, vertical sectional view through a vacuum coffee maker embodying the invention;

Fig. 2, a side elevation of a modified form of metal shell for receiving the lower water container of the vacuum coffee maker, and adapted to enclose the electric heating means and circuit therefor;

Fig. 3, a fragmentary, side elevation of the lower portion of the lower water container, showing the groove which accommodates the spring clips for holding the lower Water container rigidly in the metal shell;

Fig. 4., a top plan view of the base, showing the spring clips in the cup shape metal shell which engage the groove in the lower water container for detachably connecting it to the base;

Fig. 5, a detached, vertical, sectional view through the plastic base and the metal entering shell thereon which carries the bi-metal strip and which receives the water well of the lower water container;

Fig. 6, a diagrammatic view of the circuit for operating the heating means, showing the parts in position with the low heat circuit closed immediately after the high heat circuit has been opened by action of the bi-metal strip;

Fig. 7, a similar view of a modified form of wiring, showing the low heat circuit open at the same time that the high heat circuit is being snapped off by the action of the bi-metal strip; and

Fig. 8, a diagram of a further modification of wiring for only a high heat unit, showing the circuit in normal closed position in full lines, and in open position in broken lines.

Referring first more particularly to the construction illustrated in Figs. 1, 3, 4 and 5, the improved vacuum coffee maker to which the information pertains, includes generally the upper container ID, formed of glass, the lower container II which may be formed of either metal or glass as desired, and the base indicated generally at I2.

The upper container I0 is of generally spherical shape, having the reduced, slightly tapered lower portion [3 terminating in the depending siphon tube [4, and may be provided at its upper end with a tight fitting cover Mia.

The lower container II, which may be formed of either glass or metal as desired, may be of generally spherical shape provided at its upper, open end with the cylindrical neck [5 to receive the tapered lower portion I3 of the upper container, a rubber sealing ring l6 being located around the tapered portion l3 of the upper container so as to form an air and liquid-tight seal between the two containers at this point.

The lower container ll may be provided with a handle l1, formed of any suitable material, preferably a plastic material such as Bakelite. This handle may be attached tothe neck portion l5 of the lower container by means of a metal band l8 which is clamped around the neck I5, below the bead I9 at the upper end thereof, the ends of this band, as indicated at 20, being attached to the handle as by screws 2! or their equivalents.

A lid or cover 22, which may be formed of metal, plastic or other suitable material, is hingedly connected to the ears 23 upon the upper end of the handle, as by means of the hinge pin 24, a limit stop lug 25 being preferably formed upon the lid for contact with the top of the handle to limit the opening movement of the lid to the position shown in Fig. 1. This lid or cover is designed to fit upon the open, upper end of the neck [5 of the lower container when serving the brewed coffee beverage therefrom after the upper container has been removed.

The lower container II is provided with a peripheral groove 26, near its lower end for engagement with the spring clips 25a in the shell 5!, and has the fiat bottom wall 2'! terminating centrally in the depending, cylindrical well 28, having the closed flat bottom 29.

The base unit, indicated generally at l2, comprises the base member 30, which may be formed of plastic material such as Bakelite, of substantially disk shape with the circular shouldered portions 3! and 32 formed concentrically upon its upper side and the recess 33 in its lower side.

A cup shape metal shell 34 with flared upperend; 35 is mountedupon the central shouldered portion 32 of the base member, as by the binding screw 36, having a countersunk head 31 located in asuitable aperture in the bottom wall of the shell 34, the screw being located through a central aperture in the base member 39 and provided with a nut 38, located within the recess 33 inthe bottom of the base member.

A tension spring 39 is connected to the exterior of the cup shaped shell 34, the free end thereof being curved as at 40 and located through an aperture 41in the side wall of the shell 34 for frictional contact with the well 28 of the lower container H. as shown in Fig. 1 to hold the well 28 in contact with the other side of the shell 34.

A,-curved bi-metal strip 42 is connected at one end to the exterior of the shell34 as indicated at 4,3. in Fig 6, and normally lies close to the exterior of said shell as shown in broken lines in said figure. l

-'I hus, by means of the spring clip 39 the well 28. is held in contact with the shell 34 at the point of connection of the bi-metal strip 42, so that when the water in the well heats to the proper temperature the heat will be rapidly conveyed to the bi-metal strip. By loosening the nut. 33 the shell 34 may be rotatedclockwise or counterclockwise asdesired, for the purpose of adjusting the position of the bi-metal strip relative to the switch inorder to adjust the timing.

A metal shell 44, in the shape of a truncated cone, is provided at its lower end with aperipheral flange 45 seating upon the top of the plasticbase-rnember 3B, surroundng the shoulder portion. 31 thereof, and is attached thereto as by the screws 45.

Theupper end of the shell 44 has the inturned, annular flange 41', with V-shaped projections 48 formed therein, for attachment to the similar projections 49, upon the flat bottom flange 56 of the, shell 5|, which is cup-shaped to receive the lower portion of the lower container II. The shells 44 and 51 are rigidly connected together by means of rivets 52, located through the projections 48 and 49 respectively in the two shells. This construction bafilesheat radiation to the lower portion of the base to prevent premature operation of the switch.

A refractory block 53 is located within the lower portion of the shell 5|, for mounting electric heating unit means, indicated generally at 54 in Fig. l in such position that it will be di rectly. adjacentto the bottom of the lower container as shown in Fig. 1. This heating unit.

may be the conventional open type heating coil ordinarily used for such purposes.

The refractory block carries terminal points 55 for supplying current to the heating unit through a circuit to be later described, in which is located a switch indicated generally at 53 in Fig. 1 and adapted to be initially operated by a momentary thumbing button 51, and to be automatically operated by the bi-metal strip 42 as will be later described in detail.

Referring now to Figure 6, a diagram of the circuit for the electric heating unit is shown. The switch in this diagram comprises a central blade 58, having contact points 59 and 6!} on opposite sides thereof, at a point spaced from the fixed end of the blade, which is mounted between insulation blocks 61. This blade is connected by a wire 62 to one terminal point 55. A blade 63, for controlling the high heat unit, is fixed to one of the insulation blocks SI and has a contact point 64 thereon for contact with the point 59 upon the central blade 53, the blade 33 being connected by wire 66 with one end of the high heat unit, as indicated at 6! in Fig. 6.

A similar blade 68 is connectedto the other insulation block BI and provided with a contactpoint 69 for engagement with the contact point 68 of the central blade, for controlling the low heat unit, and this blade is connected by a wire do with one end of the low heat unit as indicated at H. The other terminal point 55 is connected by a wire 12 to a feed line, as indicated at 13, which is connected to the opposite ends of the high heat unit and low heat unit. A spring clip is diagrammatically indicated at 14 for holding the points and 69 in contact at one step of the operation as will be later described.

In Fig. 7 is shown a modified form of wiring, in which the high heat unit is controlled by a switch mechanism indicated generally at 15 and the low heat unit is controlled by a switch mechanism indicated generally at T6. The switch 15 includes two spaced blades 11 and 18, each connected at one end to an insulation block 19, and provided with contact points and 8.! respectively adapted to make contact with each other when the flexible switch blade 71 is released, and permitted to spring toward the blade l8.v A

wire 82 connects one terminal point- 55 with the -84 and having a projection 85 at its inner end:

normally engaged over the free end of the blade 11, by the. action of. the spring 86, so as to hold the contact points 80 and 81 separated.

The switch 16 comprises the short switch blade 8-? and the longer switch, blade 88, the free; end of which contacts the curved bi-metal strip'42'- Contact points 89 and 90 respectively are mounted.-

uponthe blades 8'! and 88v for contact with each other. The blade 8.! is connected by a wire-9| with theabove mentioned terminal pointand the blade 88 is connected by a wire 92. with one end of the low heat unit as indicated at i I. Theother terminal point 55 is connected by a wire 93 with a feed line as indicated at 13 which connects to. the opposite ends of the high heat unit and low 1 heat, unit. A

In Fig. 8 is shown a more simplified wiring, in,

which the switch comprises the switch blades 96 and 95, each connected at one end to an insula tion .block 96, and provided with the contact.

In this construction the m0.-

points 9 I and 98 respectively for engagement with each other. The blade 95 is connected by a wire 99 with one terminal point 55 and the blade 94 is connectedby a wire I00 with one end of the high heat unit as indicated at 61. The other terminal point 55 is connected by a wire I 0I with a feed line I02 for connection to the other end of the high heat unit. There is no low heat unit in this wiring arrangement.

In Fig. 2 is shown a modified form of base for the lower container, in which the shell 44a may be substantially like the shell 44 above described and may be mounted upon a plastic base member and it attached at its upper end to the shell 5Ia, similar to the shell 5| in Fig. 1 and adapted to receive the lower portion of the lower contaiher II. t

l-leating means and switch means as above described may be located within the shells 44a and 5m, and the momentary thumbing button 51a may be provided therein, and terminal points a may be provided for the circuit within the shells 44a and 5Ia, all in the manner above described.

In this form of the invention a curved, upright I03 is rigidly connected to one side of the shell 5| a and has at its upper end the curved spring clips I04 for engaging around the neck 55 of the lower container for holding it in the shell 5Ia,

and a handle I05 of Bakelite or other plastic material is rigidly attached to the upright I03. A lid such as shown in Fig. 1 may be attached to the handle I05.

In the operation of the improved vacuum coffee maker illustrated and above described, the proper amount of water is placed in the lower container I I, the water level for the desired amount of coffee beverage being indicated at A-A. Then the upper container I9 is placed in position as shown in Fig. 1, the rubber ring I5 forming a tight seal between the two containers, and the required amount of ground coffee is placed in the upper container. A conventional electric cord and plug is attached to the terminal points 55 connecting the same to an electric circuit, and the momentary thumbing button 51 is pushed inward.

Assuming that the wiring within the base of the device is such as shown in Fig. 6, in which the contacts and 69 are normally closed, the operation of the momentary thumbing button will move the blade 58 to the dotted line position in said figure, making contact at 59-=34 and closing the circuit to the high heat unit, the blade 58 being designed to remain in this position until moved as will be later described.

The water in the lower container II will then start to heat, the heated water from the bottom of the container rising toward the top while cold water from above circulates downward. This circulation continues up to and including the boiling point, and for a certain length of time as the water rises in temperature, pressure is created on top of the water surface A-A and finally the water starts to rise gradually in the tube I4, mingling with the ground cofiee and starting the brewing action.

As the water level lowers in the lower water container the boiling action becomes faster and more violent, causing a rapid succession of pressure escaping through the tube I4 which causes agitation or splashing above the water level in the upper container. As the water level in the lower container lowers to the bottom of the tube I4, the boiling action is very active and the heat is radiated down into the well 28, by bi-metal strip 42 becoming active and moving from the dotted line position to the full line position Fig. 6, moving the blade 58 from the dotted line position to the full line position, breaking the circuit to the high heat unit and closing the cir-' cuit through BD69 to the low heat unit, the parts being held in this position by sna ping action of the spring clip 14, and current will continue to fiow to the low heat unit to keep the coffee at drinking temperature.

If the wiring is such as shown in Fig. 7, it 'will be evident that in the normal position, as shown in dotted lines, the bimetal strip 42 will lie adjacent to the shell 34, the contacts 89 and 9D closing the circuit to the low heat unit, while the contacts and 8| will be held separated by the momentary thumbing button 83, so that the circuit to the high heat unit is open.

When the water and coffee have been placed in the lower and upper containers respectively, as above described, the terminal points 55 are connected to a live circuit and the momentary thumbing button is pushed in the direction of the arrow in Fig. '7, releasing the blade 1! and permitting it to make contact between 80 and 8|, closing the circuit to the high heat unit.

When the bi-metal strip 42 reaches the temperature causing it to flex away from the shell 34, to the full line position shown in Fig. '7, moving the blade 88 outward and separating the contacts 89 and 90, breaking the circuit to the low heat unit at the same time that the blade 1! is moved outward by the end of the bi-metal strip, opening the circuit to the high heat unit. The momentary thumbing button engages the blade TI, holding it in this position. At this time the coffee has been brewed and all contacts remain broken until the coiTee cools sufficiently to permit the bi-metal strip to return to normal position, permitting the contacts 89 and 90 to close the circuit to the low heat unit. When heated to the proper temperature the bi-metal strip will again flex, breaking the circuit, and thus cycle will continue.

The operation of the Wiirng shown in Fig. 8 is quite simple. Only one heat unit is used in this arrangement and the switch contacts are normally closed. When a live circuit is plugged into the terminal points the water will start to heat and when the set temperature is reached the bi-metal strip will flex to the dotted line position breaking contact between 9! and 98. Then as the cofiee cools the bi-metal strip will return to normal position permitting the circuit to close and thus cycle will continue.

In the foregoing description, certain terms have been used for brevity, clearness and understanding, but no unnecessary limitations are to be implied therefrom beyond the requirements of the prior art, because such words are used for descriptive purposes herein and are intended to be broadly construed.

Moreover, the embodiments of the improved construction illustrated and described herein are by way of example, and the scope of the present invention is not limited to the exact details of construction.

Having now described the invention, the construction, the operation and use of preferred embodiments thereof, and the advantageous new and useful results obtained thereby; the new and useful constructions, and reasonable mechanical equivalents thereof obvious to those skilled in the art, are set forth in the appended claims.

A Ti I'cl'aimi V v v 1. A vacuum coffee maker comprising a lower container having an open upper 'end and a reduced dep'eric'lin'g well at its lower end, a base having a cup shaped portion receiving the lower portion "of the lower container, means for detachably connecting the base to the lowe centainer, electric heating means in the bas'ega metal "shell in the base for receiving said depending well of the lower container, an electric circuit for'the heating means inthe base, aswitch in the circuit, a bi-m'e'tal strip connected atone end too'ne side of the metal shell for operating the switch, and a ten's'iori spri ngat the opposite side of the metal shell for pressing the depending wen'ag'ainst the mem Shell ali th e p bifit of connection of the "bi-metal strip. 1

2. A vacuum Coffee maker comprising a low erco fitain'e'r having an open ujiper end an a redi'iced depending w'eil atits low end; a base having a clip-"shaped portion receiving the lower portion of the lower container, means for deadjusting the metal 'shell clockwise or counterclockwise to adjust the timing.

3 3. i i-vacuum Coffee ker comprising a 'ibwr container having an open upper end and areducefi depending well at its, lower end, a base having 'a, cue-shame portion receiving the lower portion of the lower container, means for detachably connecting the base to the lower container, electric heating means in the base, a metal'shll'iri the base for receiving said depending well of the lowe container a'n electric circuit for the heating me ns" in the base, a switch in thecirc it, abi-fffi'tifl strip connected at one end todii'e side of the metal shell for operating the switch; and'a; t'ension's'pringat the cppo sit'ej'side of the nietal slfell i or {pressing the depending ,well against thejf etal she'll at thepoint of connectio'fi of the bi rn'etal strip, and means forad t ing the metal shell clockwise or counterclock wiseto'adjust thetir'n'irig. V V

ALBERT C. WILCOX.

REFERENCES CITED .fh iiidwifig references are of record in the file or this pa-tent;

' UNITED STATES PATENTS 

